Notably, TCF7, encoding the important TF (TCF1) for T cell specialization both in human and mouse,46,91 was also highly expressed in murine early innate lymphoid progenitors (EILPs) with restricted ILC potential to generate both NK and helper ILCs.19,92 In addition, in Tcf7–/– mice, Ly49a+ NK cells, ILC2s and immature ILC2s, were sharply reduced and ILC2-mediated type 2 immune responses to helminth infection was lacking,93–95 highlighting the importance of TCF7 on ILC2 development and function. The gene discussed is TF; the disease is helminthiasis.